Closest I can help is noting they show minimal signs of issues from early spring ventures where the winter crap is still being washed away. There is surface buildup on some of the bolts and on aluminum parts of my coilovers, but when I pulled everything apart to inspect the guts seemed OK. I didn't disassemble the calipers, just pads out and inspected.
That said, I'd be wary. On the other hand, you're probably doing a full bleed in the spring if not flush... Why not just swap to OEM for winters? With that much track time it seems a small time investment to avoid the compromise entirely.
Also, word from someone that drove Stoptechs and a couple weeks later my Sprints... AP Sprint is better.
not to mention lighter.